76 ANIMAL PAEASITES. 



et apparatibus ovula pariendi peculiaribus. Mares 2 aut pluribus 

 testiculorum paribus ; pene simplice. 



Ovula rotunda, inter dum in capsulas long as invaginata. Em- 

 bryones parentibus similes. 



Of Vogt's four groups 1, Pediculida; 2, Nirmida; 3, Podtirida; 

 and 4, Lepismida only the "first interests us, and if Tri- 

 chodectes should be transferred to man, also the second. 



First Family Lice = PEDICULIDA. 



Corpus planum, pellucidum ; cutis mollis, semipellucida, corio 

 similis ; caput perclare distinctum, triangular e, globuliforme, aut 

 ovale ; antennae breves, filiformes, ex 5 articulis cequalibus com- 

 posite, parum setosa ; stemmata mimina pone antennas ; rostellum 

 plane retractile, in vagina molli, infra dilatata, in apice uncinulata, 

 4 setas punctorias, pugionem formantes, conlinente inclusum. 

 Thorax parvulus, non dare articulatus, foramine 1 respiratorio in 

 utroque latere inter \, et 2, par pedum ; pedibus 6, brevibus, 

 validis anterioribus 2 interdum minoribus 9 ex brevi, crassa coxa 

 cum parvulo trochantere, ex magno, piano femore, ex parva tibia 

 et ex tarso inarticulato cum talo parvulo prominente et uncino 

 magno compositis ; abdomen magnum a thorace bene distinctum, 

 prceter in Phthiriis ; articulorum segmentis in margine perclaris 7 

 ad 9 ; superficie papillosa, aut acinulata (striis irregularibus in- 

 structa], setosa ; stigmatibus respiratoriis abdominalibus in utroque 

 latere 6. Genera sejuncta. 



From the structure of the eggs Leuckart reckons the lice to 

 the Hemiptera, which I will not omit to mention here. As, how- 

 ever, I have commenced with Vogt's classification, I have referred 

 them to the Apt era. 



The Common Louse = Pediculus capitis. (Tab. IX, figs. 9 12.) 



Synon. : Pediculus humanus, cervicalis. 



In this species the thorax is pretty distinct, elongate quadran- 

 gular, narrower than the abdomen ; the abdomen exhibits seven 

 segments notched at the margins ; the stigmata, which stand 

 upon the six anterior segments, are circular, and furnished with 

 a small opening in the middle. The stigma between the first 

 and second pairs of feet is often indistinct and resembles a small 

 papilla. The colour varies, livid or pale gray, and is said to 



